Hydraulic brake for drop hammers



HYDRAULIC BRAKE FOR DROP HAMMERS Original Filed May 10, 1928 fig 3 1 f3 b 9 14 Elli-L Julius Urbonek Rfrhur Schneider INVENTOR? CL Amw y Patented July 1 1933 JULiUs URBAnnx on vmnna, Atisriam, T'AIND AR' l I-I UR soHNnInnn, onnussnnnonr;

I it? during said upward movement, a

a HYDRAULIC; BR EFOfiDBOP EAMMERsi'i- 7' Original application filed May. 10, 1928, Serial N5. 276,

. I application 'fil ed 0ct,ober f:16,

V This invention relatesto a hydraulic brake for the tup rod of drop hammers. Drop hammers ar known in which the tup rod, for example, board, toothed rack, piston rod together with the piston and the like, are movable relative to the'tup, and in which the momentum of the rod accumulated during the drop is dissipated bya brake; Drop hammers are further known in which the momentum of the rod movable.rel ativelygtop the tup is accumulated in asteam or air chest ofthe tup cylinder, andin which the upward move ment' of therod is checked by a hydraul c brake invthetup, which brake isonly efiective -.Both of these constructions havetdisad vantages. The first mentioned construction leads by the use of-an elastlc driving med um 'to'its violent stoppage,

such as, for example, steam, 'compressedair' or the like to undesired high relative speeds between rod and'tup causing the carrier owing tobe adversely afi'ected, while the last mentioned construction requires a. very long path of retardation which mechanically isunsatisfactory.

It is also old in, the art ,to provide 'the tup with, a hydraulicbrake having two p'is tons, thelower one of which is operative only upon'descent of the tup rod againstthe tup," while the upper piston becomes operative mainly upon the ascent of the tup rod against the tup and prevents impacts between'the tup "rod and tup. Althoughfvthis construction I provides, theoretically, the best law of mol by reason in the tup.

tion for the relative movement tion well adapted for the and tup,

present invention thereto.

the highest positionvof' trated in the drawing may be again attained, l r

9 are-closed bythe 5 V I other I paths must hepro 577, and. inAnstr ia 1929, :serial No; 399,920.,

ay 31,1927. illivided andlthis v The-simplified construction ofv our inven- I 7 tion 'dispenses with the substantially constant I braklngpower duringdescent of the tup rodI gradually retarded movement of the tup rod against}'the tup-during relative ascentyit v a 4 a 'longer brakingpath, b ut yis I l r I substantially simpler andmore economical in '7 makes use of constl-uction I I 1 I Referring to Figure-1 of the denotes the tup having ,a-cavityv orf; box-e12 w r in. r c pf sa s connected by means of a" piston 3 ;The plunger 1 l -is trav ersedby ducts9 wl ich may be closed the a 1-P unger4 hic s I I, I witnth P whic .v eyt o i tai ie ky 1 piston or the like.

against theltup and also v dispenses with then 1 1 I v I valve 7.v {During the up stroke "thei tup is I entrained by the collar Thelatterjis provided. I I for reception of thebraking fluid displaced by thepi'stqf j r l On the pi to trate the tuparod tup rod. Upon'impact th e tup suddenly wee i 're itiz t p ed n gw th with a chamber 15 J Theseveral figures, of the drawing illu'sf a in the highestposition in relation tothe tup. v'lhi s rclativeapositionj; is also maintained during thei'descent ofthe" the piston and plunger't continue to descend, As result, the fluid er is displacedbeing the ducts 9 into the and partly through chamber 5,

of the ducts forced partly through only so much fluid can es cape through openg ,ing 14 as can be displaced by piston 3 in its I action, as an, immersion plunger." Inithis under-the plungp 80.1 space abovethe plunger theopeni'n'g 14"int o the l Therelation=betweenthe size; 9 andopeninglt is suchithat manner? We P event the formation over the plunger 4 of an empty space which, upon initiation, of the power for the stroke, would necessarily result in strong impacts between V 3 the tup rod and tup. H II During the up stroke of ing fluid must returnto;

the lower-side of the plunger 4 so that prior to the down stroke Inasmuchas the ducts I I valve 7 duringthe ascent of the plunger 4,

vided for the return thetup, the brak the-tup rod illus v how of the fluid. This may" be achieved plunger its highest position, path is long,

y allowing a certainamount of play of 4 iii-thebore 2 as shown in Fig. 3, or as shown in Figure 2 by-providing .certain ducts 15 in-plunger 4 which are not covered by the valvelor, as shown in Figure 4,

tling action and, consequently, also constant relative speed of the tup'rod and tup, This speed must be of such magnitude that, prior (1 'ton,'braking means-for said powerham 'ner Where" the braking toiits down stroke, the plunger 'hasreache this speed becomes so great that the collar 6 does not contact with the tup head sufficiently gently and to avoid undesirable brusqueness of contact, the construction of-Figure' i is provided' In this figure, the

' 20 in the tup' cavity;

plunger 4 is provided with a shoulder 19 which cooperates with a corresponding step this arrangement, in-

dependent-ly of the ducts 15 or the grooves '16,

provides a very effective throttling action-0t the fluidover the plunger part of the ascent; of the manner, gentleicontact duringjthe latter tup rodf In this 7 'the tup head'isassured', despite adequately reached its highest braking path isloiig, this. speed beeoinesso great thati'the collar 6 p the t'upfhead sufliciently "high-speed: of ascent ofthe plunger. i v All ofthese' means provide a eonsta'ntth'rot tlin-g action and, relative speed of consequently, also constant thetup rodand the tup. This speed must prior to its: next stroke,

position.

the plunger has Where the gently and to avoid undesirable brusqueness:'ofcontact, the construction of Figure 4is provided;

2 h construction ac O l the j:

cate' with the cylinder,

16 in theperipheryofoutlet 18 above the of the collar 6 against be ofs'uch-Inagnitude that, p h H chamber, ducts in the; plunger provid ng does not contact with. V

coating projections on the plungeranc V Figure 5j'is particularly-suitable formation of stea n -or air eushi'on'for use with th'e siinplified and inlets 17 and 18, IGSPBClZiVBlY, COHiHlUDisotha't it is overrun upon the stroke of thepiston, a cushion being formed beneath =the piston aiidf its nature being dependent ,upon the height of the e H lower; cylinder cover. Weclaim; I-

V 1. 111a power hammer comprising a tup having a cayity'containin'g' braking liquid, a tupro d pistonhaving a chamber therein and a plunger carried by the tup-rod 'pis- 3 comprising an opening in the plunger providing co nmunication between said cavity and said chambenductsin sa d plunger rethat above it, addit ional ducts adjacentithe periphery of the plunger and paths for the passageof braking the spaceabove th plunger to that below providing fluid from it, and a valve of suflicient iarea'to overlie area to overlie the second-imentioned duets Qi'iIn a POWGIllflDlmGI c'oinprising'a'tup vhaving a cavitycontaining bralting liquid, a tup rod piston having a chamber therein and a plungercarried by thetup rod piston, braking means communication between said cavity andisaid paths for the passage of braking flui'clfr'oiii the first ment oned ductsbut of insuiiicient- I V forsaid power hammer coinv prisingan opening in the plunger providing either face.of *the plunger' to the other, a j valve for clos ng certain of said" ducts, and h a "we wall to throttlejthe liquid escaping from i above the plunger during thel' tte p f p iiger ascent. v

JULIUS iiiieiiiinic V j ARTHUR SCHNEIDER- 

